U.S. TO OK DRUG FOR AIDS-RELATED ILLNESS

WASHINGTON -- Federal health officials on Tuesday decided to approve a drug widely believed to prevent a deadly AIDS-related pneumonia even though researchers have not shown conclusively that it is safe or effective.

The decision, scheduled to be announced next week, reflects a striking shift from past regulatory practice by making a drug -- pentamidine inhaled as an aerosol spray -- officially available before strictly controlled tests have proven its value.

The decision is a major victory for AIDS activists who have long argued that the government requires far too much evidence of a drug's effectiveness before allowing its release. Aerosolized pentamidine is the most promising known preventive to combat Pneumocystis carinii pneumonia, by far the most frequent cause of death of people with AIDS.

"This is a tremendous change from anything the government has ever done before with drug approval," said Jeffrey Levi, executive director of the National Gay and Lesbian Task Force. "The urgency of this epidemic has made them willing to consider new approaches."

Studies at San Francisco General Hospital showed regular use of the drug appeared to prevent onset or return of pneumocystis in a large majority of more than 400 AIDS patients on whom it was tested.

The approval is in a special category that permits promising drugs to be released for general use before they are officially licensed. Because the approval announcement is not planned until next week, federal officials would not discuss it on Tuesday. But sources said the final license will be granted to the manufacturer, LyphoMed Inc. of Rosemont, Ill., within six months.

The decision will permit physicians to prescribe the drug for those infected with the AIDS virus to prevent them from contracting pneumocystis, as the form of pneumonia is known. Many doctors already do so. Early evidence suggests that the drug may be extremely effective in preventing the pneumonia from occurring or recurring.

Sixty percent of AIDS deaths are attributed to pneumocystis, which kills from 10 percent to 50 percent of its victims the first time they get it.

Researchers at the National Institutes of Health seek to conduct controlled trials to determine whether a drug works.